Oil spills, which are the release of a liquid petroleum hydrocarbon into the environment, occur due to various reasons. The oil may be a variety of materials, including crude oil, refined petroleum products or by-products, oily refuse, or oil mixed in waste. The combination of oil and water is often termed wastewater.
Strict corporate and governmental policies dictate that constraints be placed on the quality of water discharged in the environment, including a strict limitation of residual oil in water prior to disposal. For water injection used in secondary oil recovery, is also a requirement for high water quality in order to maintain reservoir integrity. Treating oil-laden water efficiently is critical for meeting production targets as well as regulatory oil-in-water specifications.
There have been numerous attempts to find efficient, economical methods for removing oil from water, especially when the oil appears to be environmentally or ecologically detrimental. Aside from the possible danger to animal like, plant life, or marine life, oil in water ways can be a fire hazard, can present chemical problems to segments of the public or industry who may use the water in various processes, and can be wasteful and a general nuisance. In some cases, exotic or expensive oils need to be saved from loss. Among the many methods that have been taught and proposed for removing oil from water include the use of various sorption agents or sorptives. In some cases, it is possible to recover a fair amount of the oil from the sorptive by draining, squeezing, or washing with a solvent. Even when some of the oil is recovered from the sorptive, the sorptive along with residual oil is generally intended to be discarded or destroyed. There exists a need for a device that can use the sorptive without discarding or destruction.
In treatment, the oil in wastewater tends to coagulate and adhere to surrounding surfaces, particularly in sump and drain areas, and must constantly be removed from the sump to prevent clogging of the sump drain and recirculating system. In order to assist in the removal of the oil from the wastewater and to provide efficient operations, absorbing or sorptive agents have been employed in wastewater. These agents may include, but are not limited to various fumed silicas. Encapsulating the oil eliminates or minimizes the adverse properties, thereby minimizing the aforementioned clogging.
The use of hydrophobic fumed silica (HFS) as an oil sorption agent (sorptive) is known. This technology brings the hydrophobic fumed silica into contact with a mixture of oil and water. The oil becomes sorbed on the silica and the encapsulated oil is removed from the water.
For example, one approach to treating oil-laden wastewater is described in U.S. Pat. No. 4,151,078 issued Apr. 24, 1979 to Calvin. This process discusses using hydrophobic silicas, containing sorbed HF values to remove oil from water. While the use of HFS is known, due to the nature of the small, lightweight HFS particles, it is not a feasible material for many oil treatment facilities, nor the open waters of a vessel or petroleum-well based oil spill. Additionally, there remains a need for a portable collection containment system that may significantly reduce the amount of water required in a wastewater treatment system, as well as reduce the loss of fumed silica.
The presently disclosed systems and methods are directed to overcoming one or more of the problems set forth above.